In a conventional endless belt conveyor, such as used for conveying feed, forage, or other bulk materials, the conveyor belt is mounted for endless travel around a idler roll and a drive roll. During operation of the belt, there may be a tendency for the belt to drift or ride off to one side. This misalignment of the belt can cause the side edge of the belt to ride against the conveyor frame, causing wear and abrasion to both the side edge of the belt and the frame, as well as possibly tearing the belt splice. Because of this, endless belt conveyors generally include a mechanism for maintaining proper alignment of the conveyor belt. The most common manner of maintaining proper alignment of the belt is to adjust or cant one of the supporting rolls, and by adjustment of the cant on a trial and error basis, while the belt is running, proper alignment can be obtained.
Occasionally, conveyors are requied to operate in both a forward and reverse direction and it has been found that while the belt may be properly aligned when running in a forward direction, reverse travel will cause serious misalignment, with the result that the alignment must be readjusted for reverse travel. Realignment is a time consuming operation, particularly when the belt is operated in the reverse direction only for short intervals of time.
The U.S. Pat. No. 2,821,291 to Schott recognizes the belt alignment problem associated with reversible conveyors. In this patent, a belt training mechanism is employed which includes a pair of rollers that are mounted on a pivotable bracket. The side edges of the belt ride against the rollers and the thrust of the side of the belt acting through the rollers acts to skew a roller operating in contact with the lower surface of the return run of the belt to maintain alignment of the belt. When the belt in the aforementioned patent is reversed in its direction of travel, the training mechanism must be manually adjusted for the reverse travel. Thus, the device in the patent does not automatically provide alignment when operating in both the forward and reverse directions.